Multilayer ceramic electronic component

ABSTRACT

A multilayer ceramic capacitor includes a multilayer body including layered ceramic layers and internal electrode layers, and an external electrode on a side surface of the multilayer body and connected to the internal electrode layers. A recess is provided in a surface of the external electrode on one side of opposing main surfaces of the multilayer ceramic capacitor.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Japanese PatentApplication No. 2020-214913 filed on Dec. 24, 2020. The entire contentsof this application are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a multilayer ceramic electroniccomponent.

2. Description of the Related Art

An electronic device such as a portable telephone or a portable musicplayer has recently been reduced in size and/or thickness. A largenumber of multilayer ceramic electronic components are mounted on theelectronic device. With reduction in size of the electronic device, themultilayer ceramic electronic component mounted on the electronic deviceas being embedded in a substrate or mounted on a surface of thesubstrate has also increasingly been reduced in size and/or thickness.With such reduction in thickness of a multilayer ceramic capacitor, thestrength of the multilayer ceramic capacitor has been an issue.

A multilayer ceramic capacitor as described in Japanese Patent Laid-OpenNo. 2015-65394 has been proposed as a multilayer ceramic electroniccomponent having improved strength of a chip. This multilayer ceramiccapacitor is a multilayer ceramic capacitor to be embedded in a board,in which a thickness of a ceramic body in an entire chip is increased bynot allowing for an increase in a thickness of an external electrodewhile forming a band surface of the external electrode to have apredetermined length or greater for connecting the external electrode toan external wiring through a via hole, such that the occurrence ofdamage such as breakage or the like may be prevented.

The multilayer ceramic capacitor to be embedded in a board as describedin Japanese Patent Laid-Open No. 2015-65394 achieves improved flatnessof the external electrode with a reduction in thickness, and thus aheight difference at a surface of the multilayer ceramic capacitor to beembedded in a board is reduced.

Thus, in visual inspection with an image sensor or the like of a mounterfor mounting the multilayer ceramic capacitor to be embedded in a board,luminance of light reflected at the surface of the multilayer ceramiccapacitor to be embedded in a board increases, which may lead tohalation and failure in accurate recognition.

The problem arises in a general surface-mount multilayer ceramiccapacitor having improved flatness of the external electrode with areduction in thickness, without being limited to the multilayer ceramiccapacitor to be embedded in a board as in Japanese Patent Laid-Open No.2015-65394.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention provide multilayerceramic electronic components, an appearance of each of which can beaccurately checked even when having improved flatness and a reduction inthickness.

A multilayer ceramic electronic component according to a preferredembodiment of the present invention includes a multilayer body includinga plurality of layered ceramic layers and a plurality of internalelectrode layers, the multilayer body including a first main surface anda second main surface opposed to each other in a height direction, afirst side surface and a second side surface opposed to each other in awidth direction orthogonal or substantially orthogonal to the heightdirection, and a third side surface and a fourth side surface opposed toeach other in a length direction orthogonal or substantially orthogonalto the height direction and the width direction, and a plurality ofexternal electrodes on side surfaces of the multilayer body. Theplurality of internal electrode layers include a plurality of firstinternal electrode layers and a plurality of second internal electrodelayers, the plurality of first internal electrode layers and theplurality of second internal electrode layers being alternately layeredwith the ceramic layers being interposed. Each of the first internalelectrode layers includes a first drawn portion extending to at leastone of the first side surface, the second side surface, the third sidesurface, and the fourth side surface and a second drawn portionextending to at least one side surface other than the side surface towhich the first drawn portion extends. Each of the second internalelectrode layers includes a third drawn portion extending to at leastone of the first side surface, the second side surface, the third sidesurface, and the fourth side surface and a fourth drawn portionextending to at least one side surface other than the side surface towhich the third drawn portion extends. The plurality of externalelectrodes include a first external electrode connected to the firstdrawn portion and covering a portion of the first main surface, aportion of the second main surface, a portion of the first side surface,and a portion of the third side surface, a second external electrodeconnected to the second drawn portion and covering a portion of thefirst main surface, a portion of the second main surface, a portion ofthe second side surface, and a portion of the fourth side surface, athird external electrode connected to the third drawn portion andcovering a portion of the first main surface, a portion of the secondmain surface, a portion of the first side surface, and a portion of thefourth side surface, and a fourth external electrode connected to thefourth drawn portion and covering a portion of the first main surface, aportion of the second main surface, a portion of the second sidesurface, and a portion of the third side surface. A recess is in asurface of at least two external electrodes of the first externalelectrode to the fourth external electrode located on one of the firstmain surface and the second main surface.

The above and other elements, features, steps, characteristics andadvantages of the present invention will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a multilayer ceramic capacitor as anexample of a multilayer ceramic electronic component according to afirst preferred embodiment of the present invention.

FIG. 2 is a top view of the multilayer ceramic capacitor shown in FIG.1.

FIG. 3 is a bottom view of the multilayer ceramic capacitor shown inFIG. 1.

FIG. 4 is a cross-sectional view along the line IV-IV of the multilayerceramic capacitor shown in FIG. 1.

FIG. 5 is a cross-sectional view along the line V-V of the multilayerceramic capacitor shown in FIG. 1.

FIG. 6 is a cross-sectional view along the line VI-VI of the multilayerceramic capacitor shown in FIG. 1.

FIG. 7 is an exploded perspective view of a multilayer body shown inFIGS. 1 to 6.

FIG. 8A is a diagram showing a pattern of a first internal electrodelayer of the multilayer ceramic capacitor shown in FIG. 1.

FIG. 8B is a diagram showing a pattern of a second internal electrodelayer of the multilayer ceramic capacitor shown in FIG. 1.

FIG. 9A is a perspective view of a multilayer ceramic capacitor as anexample of a multilayer ceramic electronic component according to amodification of the first preferred embodiment of the present invention.

FIG. 9B is a bottom view of the multilayer ceramic capacitor accordingto the modification of the first preferred embodiment of the presentinvention.

FIG. 10 is a perspective view of the multilayer body of the multilayerceramic capacitor in FIG. 1.

FIG. 11 is a perspective view of the multilayer body shown in FIG. 10including an underlying electrode layer provided thereon.

FIG. 12 is a perspective view of the multilayer body including theunderlying electrode layer shown in FIG. 11, on which a first platedlayer is provided.

FIG. 13 is a perspective view of a multilayer ceramic capacitor as anexample of a multilayer ceramic electronic component according to asecond preferred embodiment of the present invention.

FIG. 14 is a cross-sectional view along the line XIV-XIV of themultilayer ceramic capacitor shown in FIG. 13.

FIG. 15 is a cross-sectional view along the line XV-XV of the multilayerceramic capacitor shown in FIG. 13.

FIG. 16 is a cross-sectional view along the line XVI-XVI of themultilayer ceramic capacitor shown in FIG. 13.

FIG. 17 is an exploded perspective view of a multilayer body shown inFIGS. 13 to 16.

FIG. 18A is a diagram showing a pattern of a first internal electrodelayer of the multilayer ceramic capacitor shown in FIG. 13.

FIG. 18B is a diagram showing a pattern of a second internal electrodelayer of the multilayer ceramic capacitor shown in FIG. 13.

FIG. 19 is a perspective view of the multilayer body of the multilayerceramic capacitor in FIG. 13.

FIG. 20 is a perspective view of the multilayer body shown in FIG. 19including an underlying electrode layer provided thereon.

FIG. 21 is a perspective view of the multilayer body including theunderlying electrode layer shown in FIG. 20, on which a first platedlayer is provided.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described indetail below with reference to the drawings.

1. FIRST PREFERRED EMBODIMENT (1) Multilayer Ceramic ElectronicComponent

A multilayer ceramic capacitor as an example of a multilayer ceramicelectronic component according to a first preferred embodiment of thepresent invention will be described below.

FIG. 1 is a perspective view of a multilayer ceramic capacitor as anexample of a multilayer ceramic electronic component according to thefirst preferred embodiment of the present invention. FIG. 2 is a topview of the multilayer ceramic capacitor shown in FIG. 1. FIG. 3 is abottom view of the multilayer ceramic capacitor shown in FIG. 1. FIG. 4is a cross-sectional view along the line IV-IV of the multilayer ceramiccapacitor shown in FIG. 1. FIG. 5 is a cross-sectional view along theline V-V of the multilayer ceramic capacitor shown in FIG. 1. FIG. 6 isa cross-sectional view along the line VI-VI of the multilayer ceramiccapacitor shown in FIG. 1. FIG. 7 is an exploded perspective view of amultilayer body shown in FIGS. 1 to 6. FIG. 8A is a diagram showing apattern of a first internal electrode layer of the multilayer ceramiccapacitor shown in FIG. 1. FIG. 8B is a diagram showing a pattern of asecond internal electrode layer of the multilayer ceramic capacitorshown in FIG. 1.

A multilayer ceramic capacitor 10 includes a multilayer body 12 having aparallelepiped shape and external electrodes 14 and 15.

Multilayer body 12 includes a plurality of ceramic layers 16 and aplurality of internal electrode layers 18. Multilayer body 12 includes afirst main surface 12 a and a second main surface 12 b opposed to eachother in a height direction x, a first side surface 12 c and a secondside surface 12 d opposed to each other in a length direction yorthogonal or substantially orthogonal to height direction x, and athird side surface 12 e and a fourth side surface 12 f opposed to eachother in a width direction z orthogonal or substantially orthogonal toheight direction x and length direction y. First main surface 12 a andsecond main surface 12 b extend along length direction y and widthdirection z. First side surface 12 c and second side surface 12 d extendalong height direction x and width direction z. Third side surface 12 eand fourth side surface 12 f extend along height direction x and lengthdirection y. Therefore, height direction x refers to a direction ofconnection between first main surface 12 a and second main surface 12 b,length direction y refers to a direction of connection between firstside surface 12 c and second side surface 12 d, and width direction zrefers to a direction of connection between third side surface 12 e andfourth side surface 12 f.

Multilayer body 12 preferably includes a corner and a ridgeline that arerounded. The corner refers to a portion where three surfaces ofmultilayer body 12 meet one another and the ridgeline refers to aportion where two surfaces of multilayer body 12 meet each other.Projections and recesses or the like may be provided in a portion or theentirety of first main surface 12 a and second main surface 12 b, firstside surface 12 c and second side surface 12 d, and third side surface12 e and fourth side surface 12 f.

The number of ceramic layers 16, inclusive of an outer layer, ispreferably set to at least ten and at most seven hundred, for example.

Multilayer body 12 includes an inner layer portion 20 including a singleceramic layer 16 or a plurality of ceramic layers 16 and a plurality ofinternal electrode layers 18 provided thereon. In inner layer portion20, a plurality of internal electrode layers 18 are opposed to eachother.

Multilayer body 12 includes a first main-surface-side outer layerportion 22 a located on a side of first main surface 12 a and includinga plurality of ceramic layers 16 located between first main surface 12 aand an outermost surface of inner layer portion 20 on the side of firstmain surface 12 a and a straight line extending from the outermostsurface.

Similarly, multilayer body 12 includes a second main-surface-side outerlayer portion 22 b located on a side of second main surface 12 b andincluding a plurality of ceramic layers 16 located between second mainsurface 12 b and an outermost surface of inner layer portion 20 on theside of second main surface 12 b and a straight line extending from theoutermost surface.

Multilayer body 12 includes a first side-surface-side outer layerportion 23 a located on a side of first side surface 12 c and includinga plurality of ceramic layers 16 located between first side surface 12 cand an outermost surface of inner layer portion 20 on the side of firstside surface 12 c.

Similarly, multilayer body 12 includes a second side-surface-side outerlayer portion 23 b located on a side of second side surface 12 d andincluding a plurality of ceramic layers 16 located between second sidesurface 12 d and an outermost surface of inner layer portion 20 on theside of second side surface 12 d.

Multilayer body 12 includes a third side-surface-side outer layerportion 23 c located on a side of third side surface 23 e and includinga plurality of ceramic layers 16 located between third side surface 12 eand an outermost surface of inner layer portion 20 on the side of thirdside surface 12 e.

Similarly, multilayer body 12 includes a fourth side-surface-side outerlayer portion 23 d located on a side of fourth side surface 12 f andincluding a plurality of ceramic layers 16 located between fourth sidesurface 12 f and an outermost surface of inner layer portion 20 on theside of fourth side surface 12 f.

First main-surface-side outer layer portion 22 a is an assembly of aplurality of ceramic layers 16 located on the side of first main surface12 a of multilayer body 12 and located between first main surface 12 aand internal electrode layer 18 closest to first main surface 12 a.

Second main-surface-side outer layer portion 22 b is an assembly of aplurality of ceramic layers 16 located on the side of second mainsurface 12 b of multilayer body 12 and located between second mainsurface 12 b and internal electrode layer 18 closest to second mainsurface 12 b.

As shown in FIG. 10, with a dimension in length direction y ofmultilayer body 12 being denoted as a dimension l, dimension l is, forexample, not less than about 0.43 mm and not greater than about 0.73 mm.With a dimension in width direction z being denoted as a dimension w, arelationship between dimension w and dimension l satisfies about0.85≤w/l≤ about 1.0, for example. With a dimension in height direction xbeing denoted as a t dimension, the t dimension is preferably not lessthan about 50 μm and not greater than about 90 μm, for example.

Ceramic layer 16 can be made of, for example, a dielectric material as aceramic material. For example, dielectric ceramics including a componentsuch as BaTiO₃, CaTiO₃, SrTiO₃, or CaZrO₃ can be used as a dielectricmaterial. When the aforementioned dielectric material is included as amain component, depending on a desired characteristic of multilayer body12, for example, a sub-component lower in content than the maincomponent, such as an Mn compound, an Fe compound, a Cr compound, a Cocompound, or an Ni compound may be added.

When piezoelectric ceramic is used for multilayer body 12, themultilayer ceramic electronic component defines and functions as aceramic piezoelectric element. Specific examples of a piezoelectricceramic material include a lead zirconate titanate (PZT) based ceramicmaterial.

When semiconductor ceramic is used for multilayer body 12, themultilayer ceramic electronic component defines and functions as athermistor element. Specific examples of a semiconductor ceramicmaterial include a spinel-based ceramic material.

When magnetic ceramic is used for multilayer body 12, the multilayerceramic electronic component defines and functions as an inductorelement. When the multilayer ceramic electronic component defines andfunctions as the inductor element, internal electrode layer 18 is, forexample, a coil conductor. Specific examples of the magnetic ceramicmaterial include a ferrite ceramic material.

Ceramic layer 16 between internal electrode layers 18 preferably has anaverage thickness, for example, not less than about 0.4 μm and notgreater than about 5 μm.

In multilayer ceramic capacitor 10, as shown in FIGS. 4 to 6, inmultilayer body 12, internal electrode layers 18 are alternately layeredwith ceramic layer 16 being interposed therebetween.

Multilayer body 12 includes a plurality of first internal electrodelayers 18 a and a plurality of second internal electrode layers 18 b asthe plurality of internal electrode layers 18. First internal electrodelayer 18 a and second internal electrode layer 18 b are alternatelylayered with ceramic layer 16 being interposed therebetween.

First internal electrode layer 18 a is provided on a surface of ceramiclayer 16. First internal electrode layer 18 a includes a first opposingportion 24 a opposed to first main surface 12 a and second main surface12 b and is layered in the direction of connection between first mainsurface 12 a and second main surface 12 b.

Second internal electrode layer 18 b is provided on a surface of ceramiclayer 16 different from ceramic layer 16 on which first internalelectrode layer 18 a is provided. Second internal electrode layer 18 bincludes a second opposing portion 24 b opposed to first main surface 12a and second main surface 12 b and is layered in the direction ofconnection between first main surface 12 a and second main surface 12 b.

First internal electrode layer 18 a extends to first side surface 12 cand third side surface 12 e of multilayer body 12 by a first drawnportion 26 a and extends to second side surface 12 d and fourth sidesurface 12 f of multilayer body 12 by a second drawn portion 26 b. Awidth over which first drawn portion 26 a extends to first side surface12 c may be equal or substantially equal to a width over which firstdrawn portion 26 a extends to third side surface 12 e, and a width overwhich second drawn portion 26 b extends to second side surface 12 d maybe equal or substantially equal to a width over which second drawnportion 26 b extends to fourth side surface 12 f.

In other words, first drawn portion 26 a extends toward third sidesurface 12 e of multilayer body 12 and second drawn portion 26 b extendstoward fourth side surface 12 f of multilayer body 12.

Second internal electrode layer 18 b extends to first side surface 12 cand fourth side surface 12 f of multilayer body 12 by a third drawnportion 28 a and extends to second side surface 12 d and third sidesurface 12 e of multilayer body 12 by a fourth drawn portion 28 b. Awidth over which third drawn portion 28 a extends to first side surface12 c may be equal or substantially equal to a width over which thirddrawn portion 28 a extends to fourth side surface 12 f and a width overwhich fourth drawn portion 28 b extends to second side surface 12 d maybe equal or substantially equal to a width over which fourth drawnportion 28 b extends to third side surface 12 e.

In other words, third drawn portion 28 a extends toward fourth sidesurface 12 f of multilayer body 12 and fourth drawn portion 28 b extendstoward third side surface 12 e of multilayer body 12.

First opposing portion 24 a of first internal electrode layer 18 a ispreferably, for example, rectangular or substantially rectangular,although the shape is not particularly limited. The corner may berounded or beveled.

Second opposing portion 24 b of second internal electrode layer 18 b ispreferably, for example, rectangular or substantially rectangular,although the shape is not particularly limited. The corner may berounded or beveled.

First drawn portion 26 a of first internal electrode layer 18 a ispreferably, for example, rectangular or substantially rectangular,although the shape is not particularly limited. The corner may berounded or beveled (tapered). The first drawn portion may be tapered soas to be inclined in any direction.

Second drawn portion 26 b of first internal electrode layer 18 a ispreferably, for example, rectangular or substantially rectangular,although the shape is not particularly limited. The corner may berounded or beveled (tapered). The second drawn portion may be tapered soas to be inclined in any direction.

Third drawn portion 28 a of second internal electrode layer 18 b ispreferably, for example, rectangular or substantially rectangular,although the shape is not particularly limited. The corner may berounded or beveled (tapered). The third drawn portion may be tapered soas to be inclined in any direction.

Fourth drawn portion 28 b of second internal electrode layer 18 b ispreferably, for example, rectangular or substantially rectangular,although the shape is not particularly limited. The corner may berounded or beveled (tapered). The fourth drawn portion may be tapered soas to be inclined in any direction.

First opposing portion 24 a of first internal electrode layer 18 a has alarger width than first drawn portion 26 a of first internal electrodelayer 18 a.

First opposing portion 24 a of first internal electrode layer 18 a has alarger width than second drawn portion 26 b of first internal electrodelayer 18 a.

Second opposing portion 24 b of second internal electrode layer 18 b hasa larger width than third drawn portion 28 a of second internalelectrode layer 18 b.

Second opposing portion 24 b of second internal electrode layer 18 b hasa larger width than fourth drawn portion 28 b of second internalelectrode layer 18 b.

Internal electrode layer 18 can be made of a metal such as, for example,Ni, Cu, Ag, Pd, or Au and an alloy including at least one of thosemetals, such as an Ag—Pd alloy. The number of layered internal electrodelayers 18 is preferably not less than ten and not greater than sevenhundred, for example. Internal electrode layer 18 preferably has anaverage thickness of preferably not less than about 0.2 μm and notgreater than about 2.0 μm.

A plurality of external electrodes 14 and 15 are provided on first mainsurface 12 a, second main surface 12 b, and first side surface 12 c tofourth side surface 12 f of multilayer body 12.

External electrode 14 includes a first external electrode 14 aelectrically connected to first drawn portion 26 a of first internalelectrode layer 18 a and a second external electrode 14 b electricallyconnected to second drawn portion 26 b.

First external electrode 14 a is covers first drawn portion 26 a onfirst side surface 12 c and third side surface 12 e and further covers aportion of first main surface 12 a and second main surface 12 b. Secondexternal electrode 14 b covers second drawn portion 26 b on second sidesurface 12 d and fourth side surface 12 f and further covers a portionof first main surface 12 a and second main surface 12 b.

External electrode 15 includes a third external electrode 15 aelectrically connected to third drawn portion 28 a of second internalelectrode layer 18 b and a fourth external electrode 15 b electricallyconnected to fourth drawn portion 28 b.

Third external electrode 15 a covers third drawn portion 28 a on firstside surface 12 c and fourth side surface 12 f and further covers aportion of first main surface 12 a and second main surface 12 b. Fourthexternal electrode 15 b covers fourth drawn portion 28 b on second sidesurface 12 d and third side surface 12 e and further covers a portion offirst main surface 12 a and second main surface 12 b.

In multilayer body 12, an electrical characteristic (for example, acapacitance) is provided due to first opposing portion 24 a and secondopposing portion 24 b being opposed to each other with ceramic layer 16being interposed therebetween. Therefore, the capacitance can beobtained between first external electrode 14 a and second externalelectrode 14 b to which first internal electrode layer 18 a is connectedand third external electrode 15 a and fourth external electrode 15 b towhich second internal electrode layer 18 b is connected. Therefore,multilayer ceramic capacitor 10 defines and functions as a capacitor.

A recess 30 is provided in a surface of at least two external electrodes14 and 15 of first external electrode 14 a, second external electrode 14b, third external electrode 15 a, and fourth external electrode 15 blocated on any one of first main surface 12 a and second main surface 12b. Since flatness of an external electrode surface is reduced, duringvisual inspection with an image sensor or the like of a mounter duringmounting multilayer ceramic capacitor 10, luminance of light reflectedat the surface of multilayer ceramic capacitor 10 can be reduced orprevented. Consequently, halation can be reduced or prevented and theappearance of multilayer ceramic capacitor 10 can be accuratelyrecognized.

Recess 30 has a size (area) preferably, for example, not less than about1.1% and not greater than about 34.9% of an area of external electrode14 or 15 on first main surface 12 a or second main surface 12 b whererecess 30 is provided. Since flatness of the external electrode surfacecan be reduced and luminance of reflected light can be reduced orprevented, halation can be more effectively reduced or prevented.Consequently, the appearance of multilayer ceramic capacitor 10 can bemore accurately recognized.

When the size of recess 30 is less than about 1.1% of the area ofexternal electrode 14 or 15 on first main surface 12 a or second mainsurface 12 b where recess 30 is provided, luminance of light reflectedat the external electrode surface is not reduced or prevented andhalation occurs at external electrode 14 or 15 at the time of mounting.Then, more accurate recognition of the appearance of multilayer ceramiccapacitor 10 cannot be achieved and detection of a chip based on theappearance may not be successful. When the size of recess 30 is greaterthan about 34.9% of the area of external electrode 14 or 15 on firstmain surface 12 a or second main surface 12 b where recess 30 isprovided, the appearance of the external electrode surface is poor andmountability with solder may become poor.

The size (area) of recess 30 is calculated as described below.

Specifically, in calculating the area of recess 30 in the externalelectrode surface, initially, in an LW plane of multilayer ceramiccapacitor 10, with a surface where recess 30 is present in externalelectrode 14 or 15 facing up, a profile in the height direction ofentire multilayer ceramic capacitor 10 is measured with a laserdisplacement gauge.

Thereafter, maximum dimensions in length direction y and width directionz of recess 30 are measured and measurement values are multiplied byeach other to calculate the size (area) of recess 30. Recess 30 startsfrom a portion where the height continuously decreases in the profileand ends at a portion where the height returns to the height of a planarportion.

Recess 30 has a depth preferably, for example, not less than about 2.5%and not greater than about 40% of a thickness of a third plated layer 48which will be described later. In other words, recess 30 does not extendthrough third plated layer 48. Flatness of the external electrodesurface is thus reduced, luminance of reflected light can be reduced orprevented, and an advantageous effect of reduction or prevention ofhalation can be obtained.

When the depth of recess 30 is less than about 2.5% of the thickness ofthird plated layer 48 which will be described later, luminance of lightreflected at the external electrode surface is not reduced or preventedand detection of a chip may not be successful due to halation at thetime of mounting. When the depth of recess 30 is greater than about 40%of the thickness of third plated layer 48, the appearance of theexternal electrode surface may be poor, mountability with solder may bepoor, and damage may propagate to multilayer body 12, which may lead toa defective structure.

The shape of recess 30 is not particularly limited.

The thickness of third plated layer 48 and the depth of recess 30 arecalculated as described below.

Specifically, initially, in calculating the thickness of third platedlayer 48, multilayer ceramic capacitor 10 is polished from any of firstside surface 12 c to fourth side surface 12 f as being parallel orsubstantially parallel to the polished side surface to expose across-section (an LT cross-section) as shown in FIG. 4. In the exposedcross-section, a thickness of third plated layer 48 along the heightdirection in which first main surface 12 a and second main surface 12 bare connected to each other can be measured with a microscope.

Then, in calculating the depth of recess 30, a length of a normal from areference line along the outermost surface of external electrode 14 or15 to a lowest point of recess 30 can be measured with a microscope inthe exposed cross-section. The cross-section (LT cross-section) at aposition about ½ the length in length direction y or width direction zof recess 30 is exposed.

Then, a ratio of recess 30 to third plated layer 48 can be calculatedbased on the thickness of third plated layer 48 and the depth of recess30 calculated above.

Recess 30 has a diameter preferably, for example, not less than about 20μm and not greater than about 150 μm.

The diameter of recess 30 is measured with a method described below.

Specifically, initially, in an LW plane of multilayer ceramic capacitor10, with a surface of external electrode 14 or 15 including anindentation facing up, a profile in the height direction of entiremultilayer ceramic capacitor 10 is measured with a laser displacementgauge.

Thereafter, maximum dimensions in length direction y and width directionz of recess 30 are measured and an average value thereof is defined asthe diameter of recess 30. Recess 30 starts from a portion where theheight continuously decreases in the profile and ends at a portion wherethe height returns to the height of the planar portion.

Although a position where recess 30 is provided is not particularlylimited, it is preferably provided in the center or approximate centerof the external electrode.

Although a plurality of recesses 30 may be provided, at least one recess30 is preferably provided in the surface of each of external electrodes14 and 15.

External electrodes 14 and 15 each include an underlying electrode layer40 and a plated layer 42 sequentially from the side of multilayer body12.

Underlying electrode layer 40 preferably defines and functions as a thinelectrode including, for example, at least one selected from among Ni,Cr, Cu, and Ti. The thin electrode is preferably formed with a thin filmformation method such as sputtering or vapor deposition, for example.

Underlying electrode layer 40 covers a portion of the first main surfaceand a portion of the second main surface.

Underlying electrode layer 40 has a thickness of preferably, forexample, not less than about 50 nm and not greater than about 400 nm andfurther preferably, for example, not less than about 50 nm and notgreater than about 130 nm.

Plated layer 42 preferably includes a first plated layer 44 onunderlying electrode layer 40 and on first side surface 12 c to fourthside surface 12 d, a second plated layer 46 on first plated layer 44,and third plated layer 48 on second plated layer 46. Reliability ofexternal electrodes 14 and 15 can thus be ensured.

First plated layer 44 is preferably, for example, made of a Cu platedlayer. Entry of moisture such as a plating solution can thus be reducedor prevented.

First plated layer 44 covers underlying electrode layer 40 and a portionof first side surface 12 c, a portion of second side surface 12 b, aportion of third side surface 12 e, and a portion of fourth side surface12 f.

First plated layer 44 has a thickness of preferably, for example, notless than about 2 μm and not greater than about 8 μm.

Second plated layer 46 is preferably, for example, a Ni plated layer.Erosion of a lower plated layer by solder in mounting multilayer ceramiccapacitor 10 can thus be reduced or prevented.

Second plated layer 46 covers first plated layer 44.

Second plated layer 46 has a thickness of preferably, for example, notless than about 2 μm and not greater than about 4 μm.

Third plated layer 48 is preferably, for example, an Sn plated layer.Solderability in mounting multilayer ceramic capacitor 10 can thus beimproved and multilayer ceramic capacitor 10 can be easily mounted.

Third plated layer 48 covers second plated layer 46.

Third plated layer 48 has a thickness of preferably, for example, notless than about 2 μm and not greater than about 4 μm.

The dimension in length direction y of multilayer ceramic capacitor 10is denoted as an L dimension, the dimension in height direction x ofmultilayer ceramic capacitor 10 including multilayer body 12 andexternal electrodes 14 and 15 is denoted as a T dimension, and thedimension in width direction z of multilayer ceramic capacitor 10including multilayer body 12 and external electrodes 14 and 15 isdenoted as a W dimension.

The L dimension in length direction y of multilayer ceramic capacitor 10is preferably, for example, not less than about 0.45 mm and not greaterthan about 0.75 mm.

The T dimension in height direction x of multilayer ceramic capacitor 10is preferably, for example, not less than about 70 μm and not greaterthan about 110 μm.

The W dimension in width direction z of multilayer ceramic capacitor 10preferably satisfies a condition of about 0.85≤W/L≤ about 1.0. The Tdimension in height direction x is, for example, not less than about0.04 mm and not greater than about 0.3 mm.

The dimension of multilayer ceramic capacitor 10 can be measured with amicroscope.

According to multilayer ceramic capacitor 10 shown in FIG. 1, recess 30is provided in the surface of first external electrode 14 a, secondexternal electrode 14 b, third external electrode 15 a, and fourthexternal electrode 15 b located on any one of first main surface 12 aand second main surface 12 b, and thus flatness of the externalelectrode surface is reduced. Therefore, during visual inspection withan image sensor or the like of a mounter in mounting multilayer ceramiccapacitor 10, luminance of light reflected at the surface of multilayerceramic capacitor 10 can be reduced or prevented. Consequently, halationcan be reduced or prevented and the appearance of multilayer ceramiccapacitor 10 can be accurately recognized.

In multilayer ceramic capacitor 10 shown in FIG. 1, when the ratiobetween the area of recess 30 and the area of the external electrodesurface is not less than about 1.1% and not higher than about 34.9%,luminance of light reflected at the surface of multilayer ceramiccapacitor 10 can be further reduced or prevented. Consequently, halationcan be reduced or prevented and the appearance of multilayer ceramiccapacitor 10 can be more accurately recognized.

In multilayer ceramic capacitor 10 shown in FIG. 1, when the ratiobetween the depth of recess 30 and the thickness of third plated layer48 is not less than about 2.5% and not greater than about 40%, luminanceof light reflected at the surface of multilayer ceramic capacitor 10 canbe further reduced or prevented. Consequently, halation can be reducedor prevented and the appearance of multilayer ceramic capacitor 10 canbe more accurately recognized.

A multilayer ceramic capacitor according to a modification of the firstpreferred embodiment of the present invention will now be described.FIG. 9A is a perspective view of the multilayer ceramic capacitoraccording to the modification of the first preferred embodiment. FIG. 9Bis a bottom view of the multilayer ceramic capacitor according to themodification of the first preferred embodiment. In a multilayer ceramiccapacitor 10′ shown in FIGS. 9A and 9B, elements the same orsubstantially the same as those in multilayer ceramic capacitor 10 shownin FIGS. 1 to 8B are denoted by the same reference numerals anddescription thereof will not be repeated.

Multilayer ceramic capacitor 10′ according to the modification of thefirst preferred embodiment is different from multilayer ceramiccapacitor 10 in that an external electrode is not provided on secondmain surface 12 b of multilayer body 12.

Multilayer ceramic capacitor 10′ includes multilayer body 12 have aparallelepiped shape and external electrodes 14′ and 15′.

External electrode 14′ includes a first external electrode 14 a′electrically connected to first drawn portion 26 a of first internalelectrode layer 18 a and a second external electrode 14 b′ electricallyconnected to second drawn portion 26 b.

First external electrode 14 a′ covers first drawn portion 26 a on firstside surface 12 c and third side surface 12 e and further covers aportion of first main surface 12 a. Second external electrode 14 b′covers second drawn portion 26 b on second side surface 12 d and fourthside surface 12 f and further covers a portion of first main surface 12a.

External electrode 15′ includes a third external electrode 15 a′electrically connected to third drawn portion 28 a of second internalelectrode layer 18 b and a fourth external electrode 15 b′ electricallyconnected to fourth drawn portion 28 b.

Third external electrode 15 a′ covers third drawn portion 28 a on firstside surface 12 c and fourth side surface 12 f and further covers aportion of first main surface 12 a. Fourth external electrode 15 b′covers fourth drawn portion 28 b on second side surface 12 d and thirdside surface 12 e and further covers a portion of first main surface 12a.

Recess 30 is provided in the surface of at least two external electrodes14′ and 15′ of first external electrode 14 a′, second external electrode14 b′, third external electrode 15 a′, and fourth external electrode 15b′ located on first main surface 12 a. Since flatness of the externalelectrode surface is thus reduced, during visual inspection with animage sensor or the like of a mounter in mounting multilayer ceramiccapacitor 10′, luminance of light reflected at the surface of multilayerceramic capacitor 10′ can be reduced or prevented. Consequently,halation can be reduced or prevented and the appearance of multilayerceramic capacitor 10′ can be accurately recognized.

External electrodes 14′ and 15′ each preferably include underlyingelectrode layer 40 and plated layer 42 sequentially from the side ofmultilayer body 12.

Multilayer ceramic capacitor 10′ shown in FIGS. 9A and 9B achievesadvantageous effects the same as or similar to those of multilayerceramic capacitor 10 described above and further achieves anadvantageous effect described below.

Specifically, since external electrodes 14′ and 15′ are not provided onthe surface of second main surface 12 b, in correspondence with theabsence of the thickness thereof, the thickness of multilayer body 12can be increased. Therefore, a strength of multilayer ceramic capacitor10′ and the capacitance per volume can be improved. Since wetting bysolder with respect to an upper surface (second main surface 12 b) ofmultilayer ceramic capacitor 10′ can be reduced or prevented at the timeof mounting, in correspondence therewith, the thickness of multilayerbody 12 can be further increased.

The T dimension in height direction x of multilayer ceramic capacitor10′ can be reduced, and consequently, multilayer ceramic capacitor 10′having a further reduced thickness can be obtained.

(2) Method of Manufacturing Multilayer Ceramic Capacitor

A non-limiting example of a method of manufacturing multilayer ceramiccapacitors 10 and 10′ will now be described.

Initially, a ceramic green sheet and a conductive paste for internalelectrodes are prepared. The ceramic green sheet or the conductive pastefor the internal electrodes includes a binder (for example, a knownorganic binder) and a solvent (for example, an organic solvent).

Then, an internal electrode pattern as shown in FIGS. 8A and 8B isformed by printing the conductive paste in a prescribed pattern on theceramic green sheet, for example, by gravure printing. Specifically, aconductive paste layer is formed by applying a paste including aconductive material onto the ceramic green sheet with a method such as,for example, a gravure method. For example, a paste including metalpowders to which an organic binder and an organic solvent are added isused as the paste including the conductive material. A ceramic greensheet for an outer layer including no internal electrode pattern printedthereon is also made.

Then, a multilayer sheet is made from the ceramic green sheets eachincluding the internal electrode pattern formed thereon. Specifically,the multilayer sheet is made by layering the ceramic green sheetincluding no internal electrode pattern formed thereon, alternatelylayering thereon the ceramic green sheet including the internalelectrode pattern corresponding to first internal electrode layer 18 aas shown in FIG. 8A formed thereon and the ceramic green sheet includingthe internal electrode pattern corresponding to second internalelectrode layer 18 b as shown in FIG. 8B formed thereon, and furtherlayering the ceramic green sheet including no internal electrode patternformed thereon.

Furthermore, the multilayer sheet is pressed in the direction oflayering by, for example, isostatic pressing to make a multilayer block.

In succession, the multilayer block is cut in a prescribed size toobtain a multilayer chip. A corner and a ridgeline of the multilayerchip may be rounded by barrel polishing.

Then, the multilayer chip is fired to make multilayer body 12 as shownin FIG. 10. A temperature for firing is preferably, for example, notless than about 900° C. and not greater than about 1300° C., although itis dependent on a material for ceramic or the internal electrode.

As shown in FIG. 10, first drawn portion 26 a of first internalelectrode layer 18 a is exposed at first side surface 12 c and thirdside surface 12 e of multilayer body 12, and third drawn portion 28 a ofsecond internal electrode layer 18 b is exposed at first side surface 12c and fourth side surface 12 f of multilayer body 12. Second drawnportion 26 b of first internal electrode layer 18 a is exposed at secondside surface 12 d and fourth side surface 12 f of multilayer body 12 andfourth drawn portion 28 b of second internal electrode layer 18 b isexposed at second side surface 12 d and third side surface 12 e ofmultilayer body 12.

In succession, external electrodes 14 and 15 are formed on multilayerbody 12.

Specifically, as shown in FIG. 11, in order to form first plated layer44 for covering first drawn portion 26 a of first internal electrodelayer 18 a, underlying electrode layer 40 mainly including a Ni/Cu alloyis formed by sputtering on the surface of first main surface 12 a andsecond main surface 12 b. In order to form first plated layer 44 forcovering third drawn portion 28 a of second internal electrode layer 18b as underlying electrode layer 40, underlying electrode layer 40 mainlyincluding a Ni/Cu alloy is formed by sputtering on the surface of firstmain surface 12 a and second main surface 12 b. At this time, theunderlying electrode layer does not substantially extend to the sidesurface.

Similarly, in order to form first plated layer 44 for covering seconddrawn portion 26 b of first internal electrode layer 18 a, underlyingelectrode layer 40 mainly including a Ni/Cu alloy is formed bysputtering on the surface of first main surface 12 a and second mainsurface 12 b. In order to form first plated layer for covering fourthdrawn portion 28 b of second internal electrode layer 18 b, underlyingelectrode layer 40 mainly including an Ni/Cu alloy is formed bysputtering on the surface of first main surface 12 a and second mainsurface 12 b. At this time, the underlying electrode layer does notsubstantially extend to the side surface.

In succession, as shown in FIG. 12, first plated layer 44 is formed byCu plating to be continuous to a surface of a portion of first sidesurface 12 c and third side surface 12 e and a surface of a portion offirst main surface 12 a and second main surface 12 b to cover firstdrawn portion 26 a of first internal electrode layer 18 a exposed atfirst side surface 12 c and third side surface 12 e of multilayer body12 and underlying electrode layer 40. First plated layer 44 is formed byCu plating to be continuous to a surface of a portion of first sidesurface 12 c and fourth side surface 12 f and a surface of a portion offirst main surface 12 a and second main surface 12 b to cover thirddrawn portion 28 a of second internal electrode layer 18 b exposed atfirst side surface 12 c and fourth side surface 12 f of multilayer body12.

Similarly, first plated layer 44 is formed by Cu plating to becontinuous to a surface of a portion of second side surface 12 d andfourth side surface 12 f and a surface of a portion of first mainsurface 12 a and second main surface 12 b to cover second drawn portion26 b of first internal electrode layer 18 a exposed at second sidesurface 12 d and fourth side surface 12 f of multilayer body 12. Firstplated layer 44 is formed by Cu plating to be continuous to a surface ofa portion of second side surface 12 d and third side surface 12 e and asurface of a portion of first main surface 12 a and second main surface12 b to cover fourth drawn portion 28 b of second internal electrodelayer 18 b exposed at second side surface 12 d and third side surface 12e of multilayer body 12.

In forming external electrodes 14′ and 15′ but not on second mainsurface 12 b as in multilayer ceramic capacitor 10′, underlyingelectrode layer 40 is not formed on second main surface 12 b.

Then, second plated layer 46 is formed to cover the surface of firstplated layer 44. For example, an Ni plated layer is formed as secondplated layer 46.

Furthermore, third plated layer 48 is formed to cover the surface ofsecond plated layer 46. For example, an Sn plated layer is formed asthird plated layer 48.

In succession, recess 30 is formed in the surface of external electrodes14 and 15 located on first main surface 12 a or second main surface 12b.

In providing recess 30, recess 30 is provided by pressing a rod that ismade of a metal and is capable of cutting, against a portion whererecess 30 is desired in the surface of external electrodes 14 and 15. Bychanging a diameter of the metal rod or a depth of pressing, the depth,the diameter, and the area of recess 30 can be changed and adjusted.

Multilayer ceramic capacitor 10 as shown in FIG. 1 or multilayer ceramiccapacitor 10′ as shown in FIGS. 9A and 9B is manufactured as set forthabove.

2. SECOND PREFERRED EMBODIMENT

A multilayer ceramic capacitor as an example of a multilayer ceramiccomponent according to a second preferred embodiment of the presentinvention will be described below.

FIG. 13 is a perspective view of the multilayer ceramic capacitor in thesecond preferred embodiment. FIG. 14 is a cross-sectional view along theline XIV-XIV of the multilayer ceramic capacitor shown in FIG. 13. FIG.15 is a cross-sectional view along the line XV-XV of the multilayerceramic capacitor shown in FIG. 13. FIG. 16 is a cross-sectional viewalong the line XVI-XVI of the multilayer ceramic capacitor shown in FIG.13. FIG. 17 is an exploded perspective view of a multilayer body shownin FIGS. 13 to 16. FIG. 18A is a diagram showing a pattern of a firstinternal electrode layer of the multilayer ceramic capacitor shown inFIG. 13. FIG. 18B is a diagram showing a pattern of a second internalelectrode layer of the multilayer ceramic capacitor shown in FIG. 13.Elements of a multilayer ceramic capacitor 110 shown in FIGS. 13 to 18Bthat are the same or substantially the same as those of multilayerceramic capacitor 10 shown in FIGS. 1 to 5 are denoted by the samereference numerals and description thereof will not be repeated.

Multilayer ceramic capacitor 110 includes multilayer body 12 having aparallelepiped shape and external electrodes 114 and 115.

Multilayer body 12 includes a plurality of ceramic layers 16 and aplurality of internal electrode layers 118.

In multilayer ceramic capacitor 110, as shown in FIGS. 14 to 16, inmultilayer body 12, internal electrode layers 118 are alternatelylayered with ceramic layer 16 being interposed therebetween.

Multilayer body 12 includes a plurality of first internal electrodelayers 118 a and a plurality of second internal electrode layers 118 bas the plurality of internal electrode layers 118. First internalelectrode layer 118 a and second internal electrode layer 118 b arealternately layered with ceramic layer 16 being interposed therebetween.

First internal electrode layer 118 a is provided on a surface of ceramiclayer 16. First internal electrode layer 118 a includes first opposingportion 24 a opposed to first main surface 12 a and second main surface12 b and is layered in the direction of connection between first mainsurface 12 a and second main surface 12 b.

Second internal electrode layer 118 b is provided on a surface ofceramic layer 16 different from ceramic layer 16 on which first internalelectrode layer 118 a is provided. Second internal electrode layer 118 bincludes second opposing portion 24 b opposed to first main surface 12 aand second main surface 12 b and is layered in the direction ofconnection between first main surface 12 a and second main surface 12 b.

First internal electrode layer 118 a extends to first side surface 12 cof multilayer body 12 by first drawn portion 26 a and extends to secondside surface 12 d of multilayer body 12 by second drawn portion 26 b.First drawn portion 26 a extends toward third side surface 12 e ofmultilayer body 12 and second drawn portion 26 b extends toward fourthside surface 12 f of multilayer body 12.

Second internal electrode layer 118 b extends to first side surface 12 cof multilayer body 12 by third drawn portion 28 a and extends to secondside surface 12 d of multilayer body 12 by fourth drawn portion 28 b.Third drawn portion 28 a extends toward fourth side surface 12 f ofmultilayer body 12 and fourth drawn portion 28 b extends toward thirdside surface 12 c of multilayer body 12.

First internal electrode layer 118 a and second internal electrode layer118 b are not exposed at third side surface 12 e and fourth side surface12 f of multilayer body 12.

First drawn portion 26 a of first internal electrode layer 118 a mayextend to one of first side surface 12 c, second side surface 12 d,third side surface 12 e, and fourth side surface 12 f, and in that case,second drawn portion 26 b of first internal electrode layer 118 a mayextend to one side surface other than the side surface where first drawnportion 26 a is drawn.

Third drawn portion 28 a of second internal electrode layer 118 b mayextend to one of first side surface 12 c, second side surface 12 d,third side surface 12 e, and fourth side surface 12 f, and fourth drawnportion 28 b of second internal electrode layer 118 b may extend to onesurface other than the side surface where third drawn portion 28 a isdrawn.

When multilayer ceramic capacitor 110 is viewed in height direction x, astraight line that connects first drawn portion 26 a and second drawnportion 26 b of first internal electrode layer 118 a to each otherpreferably intersects with a straight line that connects third drawnportion 28 a and fourth drawn portion 28 b of second internal electrodelayer 118 b to each other.

Furthermore, in side surfaces 12 c, 12 d, 12 e, and 12 f of multilayerbody 12, preferably, first drawn portion 26 a of first internalelectrode layer 118 a and fourth drawn portion 28 b of second internalelectrode layer 118 b extend to positions opposed to each other, andsecond drawn portion 26 b of first internal electrode layer 118 a andthird drawn portion 28 a of second internal electrode layer 18 b extendto positions opposed to each other.

External electrodes 114 and 115 are provided on first main surface 12 a,second main surface 12 b, first side surface 12 c, and second sidesurface 12 d of multilayer body 12.

External electrode 114 includes a first external electrode 114 aelectrically connected to first drawn portion 26 a of first internalelectrode layer 118 a and a second external electrode 114 b electricallyconnected to second drawn portion 26 b.

First external electrode 114 a covers first drawn portion 26 a on firstside surface 12 c and covers a portion of first main surface 12 a,second main surface 12 b, and third side surface 12 e. Second externalelectrode 114 b covers second drawn portion 26 b on second side surface12 d and covers a portion of first main surface 12 a, second mainsurface 12 b, and fourth side surface 12 f.

External electrode 115 includes a third external electrode 115 aelectrically connected to third drawn portion 28 a of second internalelectrode layer 118 b and a fourth external electrode 115 b electricallyconnected to fourth drawn portion 28 b.

Third external electrode 115 a covers third drawn portion 28 a on firstside surface 12 c and covers a portion of first main surface 12 a,second main surface 12 b, and fourth side surface 12 f. Fourth externalelectrode 115 b covers fourth drawn portion 28 b on second side surface12 d and covers a portion of first main surface 12 a, second mainsurface 12 b, and third side surface 12 e.

Furthermore, as shown in FIG. 13, external electrodes 114 and 115 onthird side surface 12 e or fourth side surface 12 f where internalelectrode layer 118 does not extend preferably cover in a bracket shape,any one short side of the side surface where internal electrode layer118 does not extend and a portion from ends of the short side toportions intermediate between opposing long sides.

In multilayer body 12, first opposing portion 24 a and second opposingportion 24 b are opposed to each other with ceramic layer 16 beinginterposed therebetween, so that an electrical characteristic (forexample, a capacitance) is provided. Therefore, the capacitance can beobtained between first external electrode 114 a and second externalelectrode 114 b to which first internal electrode layer 118 a isconnected and third external electrode 115 a and fourth externalelectrode 115 b to which second internal electrode layer 118 b isconnected. Therefore, multilayer ceramic capacitor 110 defines andfunctions as a capacitor.

Recess 30 is provided in a surface of at least two external electrodes114 and 115 of first external electrode 114 a, second external electrode114 b, third external electrode 115 a, and fourth external electrode 115b located on any one of first main surface 12 a and second main surface12 b. Since flatness of the external electrode surface is thus reduced,during visual inspection with an image sensor or the like of a mounterin mounting multilayer ceramic capacitor 110, luminance of lightreflected at the surface of multilayer ceramic capacitor 110 can bereduced or prevented. Consequently, halation can be reduced or preventedand the appearance of multilayer ceramic capacitor 110 can be accuratelyrecognized.

External electrodes 114 and 115 each preferably include underlyingelectrode layer 40 and plated layer 42 sequentially from the side ofmultilayer body 12.

Multilayer ceramic capacitor 110 shown in FIG. 13 achieves advantageouseffects the same as or similar to those of multilayer ceramic capacitor10 according to the first preferred embodiment.

(1) Method of Manufacturing Multilayer Ceramic Electronic Component

A non-limiting example of a method of manufacturing multilayer ceramiccapacitor 110 as the multilayer ceramic electronic component will now bedescribed.

Initially, a ceramic green sheet and a conductive paste for internalelectrodes are prepared. The ceramic green sheet or the conductive pastefor the internal electrodes includes a binder (for example, a knownorganic binder) and a solvent (for example, an organic solvent).

Then, an internal electrode pattern as shown in FIGS. 18A and 18B isformed by printing the conductive paste in a prescribed pattern on theceramic green sheet, for example, by gravure printing. Specifically, aconductive paste layer is formed by applying a paste including aconductive material onto the ceramic green sheet with a method such asgravure printing, for example. For example, a paste including metalpowders to which an organic binder and an organic solvent are added isused as the paste including the conductive material. A ceramic greensheet for an outer layer including no internal electrode pattern printedthereon is also made.

A multilayer sheet is made from the ceramic green sheets each includingthe internal electrode pattern formed thereon. Specifically, themultilayer sheet is made by layering the ceramic green sheet includingno internal electrode pattern formed thereon, alternately layeringthereon the ceramic green sheet including the internal electrode patterncorresponding to first internal electrode layer 118 a as shown in FIG.18A formed thereon and the ceramic green sheet including the internalelectrode pattern corresponding to second internal electrode layer 118 bas shown in FIG. 18B formed thereon, and further layering the ceramicgreen sheet including no internal electrode pattern formed thereon.

Furthermore, the multilayer sheet is pressed in the direction oflayering by, for example, isostatic pressing to make a multilayer block.

Then, the multilayer block is cut in a prescribed size to obtain amultilayer chip. A corner and a ridgeline of the multilayer chip may berounded by barrel polishing.

Then, the multilayer chip is fired to make multilayer body 12 as shownin FIG. 19. A temperature for firing is preferably, for example, notless than about 900° C. and not greater than about 1300° C., although itis dependent on a material for ceramic or the internal electrode.

As shown in FIG. 20, first drawn portion 26 a of first internalelectrode layer 118 a and third drawn portion 28 a of second internalelectrode layer 118 b are exposed at first side surface 12 c ofmultilayer body 12. Second drawn portion 26 b of first internalelectrode layer 118 a and fourth drawn portion 28 b of second internalelectrode layer 118 b are exposed at second side surface 12 d ofmultilayer body 12.

In succession, external electrodes 114 and 115 are formed on multilayerbody 12.

Specifically, in order to form first plated layer 44 for covering firstdrawn portion 26 a of first internal electrode layer 118 a, underlyingelectrode layer 40 mainly including a Ni/Cu alloy is formed bysputtering on the surface of first main surface 12 a and second mainsurface 12 b. In order to form first plated layer for covering thirddrawn portion 28 a of second internal electrode layer 118 b, underlyingelectrode layer 40 mainly including a Ni/Cu alloy is formed bysputtering on the surface of first main surface 12 a and second mainsurface 12 b. At this time, the underlying electrode layer does notsubstantially extend to the side surface.

Similarly, in order to form first plated layer 44 for covering seconddrawn portion 26 b of first internal electrode layer 118 a, underlyingelectrode layer 40 mainly including a Ni/Cu alloy is formed bysputtering on the surface of first main surface 12 a and second mainsurface 12 b. In order to form first plated layer for covering fourthdrawn portion 28 b of second internal electrode layer 118 b, underlyingelectrode layer 40 mainly including a Ni/Cu alloy is formed bysputtering on the surface of first main surface 12 a and second mainsurface 12 b. At this time, the underlying electrode layer does notsubstantially extend to the side surface.

In succession, first plated layer 44 is formed by Cu plating tocontinuous to a surface of a portion of first side surface 12 c and asurface of a portion of first main surface 12 a and a portion of secondmain surface 12 b to cover first drawn portion 26 a of first internalelectrode layer 118 a exposed at first side surface 12 c of multilayerbody 12 and underlying electrode layer 40.

First plated layer 44 is formed by Cu plating to be continuous to asurface of a portion of second side surface 12 d and a surface of aportion of first main surface 12 a and a portion of second main surface12 b to cover second drawn portion 26 b of first internal electrodelayer 118 a exposed at second side surface 12 d of multilayer body 12.

Similarly, first plated layer 44 is formed by Cu plating to becontinuous to a surface of a portion of first side surface 12 c and asurface of a portion of first main surface 12 a and a portion of secondmain surface 12 b to cover third drawn portion 28 a of second internalelectrode layer 118 b exposed at first side surface 12 c of multilayerbody 12.

First plated layer 44 is formed by Cu plating to be continuous to asurface of a portion of second side surface 12 d and a surface of aportion of first main surface 12 a and a portion of second main surface12 b to cover fourth drawn portion 28 b of second internal electrodelayer 118 b exposed at second side surface 12 d of multilayer body 12.

Then, second plated layer 46 is formed to cover the surface of firstplated layer 44. A Ni plated layer, for example, is formed as secondplated layer 46.

Furthermore, third plated layer 48 is formed to cover the surface ofsecond plated layer 46. A Sn plated layer, for example, is formed asthird plated layer 48.

Then, with plated layer 42, external electrodes 114 and 115 arranged onthe side surface where internal electrode layer 118 does not extend isformed in a bracket shape to cover opposing short sides of the sidesurface where internal electrode layer 118 does not extend and portionsfrom the ends of the opposing short sides to portions intermediatebetween opposing long sides.

Thereafter, recess 30 is provided in the surface of external electrodes114 and 115 with a method the same as or similar to that for multilayerceramic capacitor 10 in the first preferred embodiment.

Multilayer ceramic capacitor 110 as shown in FIG. 13 is manufactured asset forth above.

3. EXPERIMENTAL EXAMPLE

Advantageous effects of the multilayer ceramic capacitor obtained as setforth above will become apparent from experimental examples below.

A multilayer ceramic capacitor having the structure shown in FIGS. 1 to6 was made in accordance with the non-limiting example of amanufacturing method as the multilayer ceramic electronic componentaccording to a preferred embodiment of the present invention describedabove, and whether or not halation occurred during a mounter was checkedand a state of the recess was visually inspected.

(1) Specifications in Examples

In Examples of a preferred embodiment of the present invention, samplesof the multilayer ceramic capacitors in Examples 1 to 21 withspecifications as described below were made in accordance with thenon-limiting example of a method of manufacturing the multilayer ceramiccapacitor described in the first preferred embodiment above.

Specifications common to the multilayer ceramic capacitors in Examplesare as below.

-   -   Specifications of samples    -   Dimension of multilayer ceramic capacitor: see Tables 1 and 2    -   Material for ceramic layer: BaTiO₃    -   Capacitance: about 220 nF    -   Rated voltage: about 4 V    -   Internal electrode layer    -   Pattern of internal electrode layer: see FIGS. 8A and 8B    -   Material for internal electrode: Ni    -   Structure of external electrode    -   Underlying electrode layer        -   Composed of underlying electrode layer, first plated layer,            second plated layer, and third plated layer        -   Underlying electrode layer: thin electrode (sputtered            electrode) formed by sputtering        -   Material for underlying electrode layer: alloy containing            Ni, Cr, and Cu        -   Thickness of underlying electrode layer: about 200 nm    -   Plated layer        -   Material for first plated layer: Cu        -   Thickness of first plated layer: about 5 μm        -   Material for second plated layer: Ni        -   Thickness of second plated layer: about 3 μm        -   Material for third plated layer: Sn        -   Thickness of third plated layer: about 3 μm    -   Structure of recess    -   Position where recess is provided: provided in center of        external electrode    -   Area of recess: see Tables 1 and 2    -   Depth of recess: see Tables 1 and 2

(2) Specifications in Comparative Example

Samples of the multilayer ceramic capacitors in which no recess wasprovided in the external electrode were made as Comparative Example.

The multilayer ceramic capacitors in Comparative Example were made inaccordance with the method of manufacturing the multilayer ceramiccapacitor described in the first preferred embodiment. The material forthe ceramic layer, the material for the internal electrode, or otherwiseis in common to Examples.

Table 1 shows specifications of the multilayer ceramic capacitors inComparative Example.

(3) Method of Measuring and Calculating Each Dimension (a) Method ofMeasuring Dimension in Length Direction of External Electrode Surface

In measuring a dimension in the length direction of the externalelectrode surface in each sample, a dimension in the length direction ofany of the first to fourth external electrodes formed on the first mainsurface or the second main surface was measured with a microscope.

(b) Method of Measuring Dimension in Width Direction of ExternalElectrode Surface

In measuring a dimension in the width direction of the externalelectrode in each sample, a dimension in the width direction of any ofthe first to fourth external electrodes formed on the first main surfaceor the second main surface was measured with a microscope.

(c) Method of Calculating Area of External Electrode Surface

An area of the external electrode surface was calculated from thedimension in the length direction of the external electrode surface andthe dimension in the width direction of the external electrode surfacemeasured with the method described above.

(d) Method of Calculating Diameter of Recess

A diameter of the recess in the external electrode surface was measuredwith a method below.

Specifically, initially, in the LW plane of the multilayer ceramiccapacitor, with the surface of the external electrode including anindentation facing up, the profile in the height direction of the entiremultilayer ceramic capacitor was measured with a laser displacementgauge.

Thereafter, maximum lengths in length direction y and width direction zof the recess were measured and an average value thereof was defined asthe diameter of the recess. The recess is assumed to start from aportion where the height continuously decreases on the profile and endsat a portion where the height returns to the height of the planarportion.

(e) Method of Calculating Area of Recess

In calculating an area of the recess in the external electrode surface,in the LW plane of the multilayer ceramic capacitor representing thesample, with the surface of the external electrode including the recessfacing up, the profile in the height direction of the entire multilayerceramic capacitor was measured with a laser displacement gauge.

Thereafter, maximum lengths in length direction y and width direction zof the recess were measured and the area of the recess was calculated bymultiplying the maximum lengths by each other. The recess is assumed tostart from a portion where the height continuously decreases on theprofile and ends at a portion where the height returns to the height ofthe planar portion.

(f) Method of Calculating Ratio Between Area of Recess and Area ofExternal Electrode Surface

A ratio between the area of the recess and the area of the externalelectrode surface was calculated from the area of the recess and thearea of the external electrode surface calculated with the methoddescribed above. Specifically, the ratio between the area of the recessand the area of the external electrode surface was calculated as theratio=(area of recess)/(area of external electrode surface).

(g) Method of Measuring Thickness of Third Plated Layer and Depth ofRecess

In measuring the thickness of the third plated layer, the multilayerceramic capacitor representing the sample was polished from any of thefirst to fourth side surfaces as being substantially in parallel to thepolished side surface to expose, for example, a cross-section (LTcross-section) as shown in FIG. 4. A value of the thickness of the thirdplated layer measured with a microscope in the exposed cross-sectionalong the height direction in which the first main surface and thesecond main surface were connected to each other was defined as thethickness of the third plated layer.

In measuring the depth of the recess, a value of the length of thenormal from the reference line along the outermost surface of theexternal electrode to the lowest point of the recess was measured with amicroscope in the LT cross-section exposed with the method describedabove, and this value was defined as the depth of the recess. Across-section (LT cross-section) at a position about ½ the length inlength direction y or width direction z of recess 30 was exposed.

(h) Method of Calculating Ratio Between Depth of Recess and Thickness ofThird Plated Layer

A ratio between the depth of the recess and the thickness of the thirdplated layer was calculated from the value of the depth of the recessand the value of the thickness of the third plated layer measured withthe method described above. Specifically, the ratio between thethickness of the third plated layer and the depth of the recess wascalculated as the ratio=(value of depth of recess)/(value of thicknessof third plated layer).

(4) Method of Checking Whether or Not Halation Occurred in Mounter

A reel in which a multilayer ceramic capacitor representing the samplehad been tape-packaged was prepared. An error in recognition of thesample that occurred in taking the multilayer ceramic capacitor out ofthe reel by using the mounter was regarded as occurrence of halation,and it was counted as the number of times of occurrence of halation. Ineach of Examples and Comparative Example, the number of samples was setto one thousand.

(5) Method of Checking State of Recess by Visual Inspection

With the external electrode surface of the multilayer ceramic capacitorrepresenting the sample including the recess facing up, this uppersurface was observed with a microscope at a 20-fold magnification. Astate that substantially no recess was observed in the externalelectrode surface and a state that the recess occupied approximatelymore than 30% of the external electrode surface were determined as poorappearance. In each of Examples and Comparative Example, the number ofsamples was set to one thousand.

Tables 1 and 2 show results of experiments for each of Examples andComparative Example above.

TABLE 1 Comparative Example Example Example Example Example Example ItemExample 1 2 3 4 5 6 L Dimension (μm) 200 200 150 250 250 150 250 ofExternal Electrode Surface W Dimension (μm) 200 200 150 250 250 150 250of External Electrode Surface Area of (μm²) 40000 40000 22500 6250062500 22500 62500 External Electrode Surface Thickness (μm) 3.2 3.2 2.54 4 2.5 4 of Third Plated Layer Diameter (μm) — 70 70 70 30 100 100 ofRecess Area of (μm²) — 3,848 3,848 3,848 707 7,854 7,854 Recess Depth of(μm) — 0.5 0.5 0.5 0.5 0.5 0.1 Recess Area of Recess/ — 9.6% 17.1% 6.2%1.1% 34.9% 12.6% Area of External Electrode Depth of Recess/ — 15.6%20.0% 12.5% 12.5% 20.0% 2.5% Thickness of Third Sn Plated LayerOccurrence of (Count) 752/1000 0/1000 0/1000 0/1000 2/1000 0/1000 0/1000Halation Checked State of (Count)  0/1000 0/1000 0/1000 0/1000 0/10000/1000 0/1000 Recess by Visual Inspection Example Example ExampleExample Example Example Item 7 8 9 10 11 12 L Dimension (μm) 150 200 250200 150 200 of External Electrode Surface W Dimension (μm) 150 200 250200 150 200 of External Electrode Surface Area of (μm²) 22500 4000062500 40000 22500 40000 External Electrode Surface Thickness (μm) 2.53.2 3.2 3.2 2.5 3.2 of Third Plated Layer Diameter (μm) 100 20 20 110110 150 of Recess Area of (μm²) 7,854 314 314 9,503 9,503 17,671 RecessDepth of (μm) 1 0.5 0.5 0.5 0.5 0.5 Recess Area of Recess/ 34.9% 0.8%0.5% 23.8% 42.2% 44.2% Area of External Electrode Depth of Recess/ 40.0%15.6% 15.6% 15.6% 20.0% 15.6% Thickness of Third Sn Plated LayerOccurrence of (Count) 0/1000 57/1000 180/1000 0/1000  0/1000  0/1000Halation Checked State of (Count) 0/1000  0/1000  0/1000 0/1000 10/100045/1000 Recess by Visual Inspection

TABLE 2 Example Example Example Example Example Example Example ExampleExample Item 13 14 15 16 17 18 19 20 21 L Dimension (μm) 200 150 250 150250 250 150 250 150 of External Electrode Surface W Dimension (μm) 200150 250 150 250 250 150 250 150 of External Electrode Surface Area of(μm²) 40000 22500 62500 22500 62500 02500 22500 62500 22500 ExternalElectrode Surface Thickness (μm) 3.2 2.5 4 2.5 4 4 2.5 4 2.5 of ThirdPlated Layer Diameter of (μm) 70 70 70 70 70 70 70 70 70 Recess Area of(μm²) 3,848 3,848 3,848 3,848 3,848 3,848 3,848 3,848 3,848 Recess Depthof (μm) 0.5 0.5 0.5 1 0.1 0.05 0.05 1.5 1.5 Recess Area of Recess/ 9.6%17.1% 6.2% 17.1% 6.2% 6.2% 17.1% 6.2% 17.1% Area of External ElectrodeDepth of Recess/ 15.6% 20.0% 12.5% 40.0% 2.5% 1.3% 2.0% 37.5% 60.0%Thickness of Third Sn Plated Layer Occurrence of (Count) 0/1000 0/10000/1000 0/1000 0/1000 160/1000 290/1000 0/1000  0/1000 Halation CheckedState of (Count) 0/1000 0/1000 0/1000 3/1000 0/1000  0/1000  0/10000/1000 120/1000 Recess by Visual Inspection

In Tables 1 and 2, in the multilayer ceramic capacitors representing thesamples in Examples 1 to 21, the recess was provided in the surface ofthe external electrode. Therefore, the occurrence of halation wasrelatively less often and the state of the recess provided in theexternal electrode surface was also relatively good.

In Examples 8 and 9, the ratio between the area of the recess and thearea of the external electrode surface was equal to or less than about1.1%. Therefore, in Example 8, halation occurred in fifty-sevenmultilayer ceramic capacitors among one thousand multilayer ceramiccapacitors, and in Example 9, halation occurred in one hundred andeighty multilayer ceramic capacitors among one thousand multilayerceramic capacitors.

In Examples 11 and 12, the ratio between the area of the recess and thearea of the external electrode surface was equal to or greater thanabout 34.9%. Therefore, in Example 11, appearance was poor in tenmultilayer ceramic capacitors among one thousand multilayer ceramiccapacitors, and in Example 12, appearance was poor in forty-fivemultilayer ceramic capacitors among one thousand multilayer ceramiccapacitors.

In Examples 18 and 19, the ratio between the depth of the recess and thethickness of the third plated layer was equal to or less than about2.5%. Therefore, in Example 18, halation occurred in one hundred andsixty multilayer ceramic capacitors among one thousand multilayerceramic capacitors, and in Example 19, halation occurred in two hundredand ninety multilayer ceramic capacitors among one thousand multilayerceramic capacitors.

In Example 21, the ratio between the depth of the recess and thethickness of the third plated layer was equal to or greater than about40%. Therefore, appearance was poor in one hundred and twenty multilayerceramic capacitors among one thousand multilayer ceramic capacitors.

In the results above, in Examples 1 to 7, 10, 13 to 17, and 20, theratio between the area of the recess and the area of the externalelectrode surface was not less than about 1.1% and not greater thanabout 34.9%. Therefore, halation occurred in zero multilayer ceramiccapacitors or in relatively few of the multilayer ceramic capacitors,and appearance was also poor in zero multilayer ceramic capacitors or inrelatively few of the multilayer ceramic capacitors.

In Examples 1 to 7, 10, 13 to 17, and 20, the ratio between the depth ofthe recess and the thickness of the third plated layer was not less thanabout 2.5% and not greater than about 40%. Therefore, halation occurredin zero multilayer ceramic capacitor or in relatively few multilayerceramic capacitors, and appearance was also poor in zero multilayerceramic capacitor or in relatively few multilayer ceramic capacitors.

In Comparative Example, no recess was provided in the external electrodesurface. Therefore, halation occurred in 752 multilayer ceramiccapacitors among one thousand multilayer ceramic capacitors.

As seen in the results above, the recess in the surface of the externalelectrode of the multilayer ceramic capacitor leads to reduced flatnessof the external electrode surface, and luminance of light reflected atthe surface of the multilayer ceramic capacitor can be reduced orprevented in visual inspection with an image sensor or the like of amounter in mounting the multilayer ceramic capacitor. Consequently, itwas confirmed that halation could be reduced or prevented and theappearance of the multilayer ceramic capacitor could be accuratelyrecognized.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

What is claimed is:
 1. A multilayer ceramic electronic componentcomprising: a multilayer body including a plurality of layered ceramiclayers and a plurality of internal electrode layers, the multilayer bodyincluding a first main surface and a second main surface opposed to eachother in a height direction, a first side surface and a second sidesurface opposed to each other in a width direction orthogonal orsubstantially orthogonal to the height direction, and a third sidesurface and a fourth side surface opposed to each other in a lengthdirection orthogonal or substantially orthogonal to the height directionand the width direction; and a plurality of external electrodes on thefirst, second, third, and fourth side surfaces of the multilayer body;wherein the plurality of internal electrode layers include a pluralityof first internal electrode layers and a plurality of second internalelectrode layers, the plurality of first internal electrode layers andthe plurality of second internal electrode layers being alternatelylayered with the ceramic layers being interposed therebetween; each ofthe plurality of first internal electrode layers includes a first drawnportion extending to at least one of the first side surface, the secondside surface, the third side surface, and the fourth side surface and asecond drawn portion extending to at least one side surface other thanthe side surface to which the first drawn portion extends; each of thesecond internal electrode layers includes a third drawn portionextending to at least one of the first side surface, the second sidesurface, the third side surface, and the fourth side surface and afourth drawn portion extending to at least one side surface other thanthe side surface to which the third drawn portion extends; the pluralityof external electrodes include: a first external electrode connected tothe first drawn portion and covering a portion of the first mainsurface, a portion of the second main surface, a portion of the firstside surface, and a portion of the third side surface; a second externalelectrode connected to the second drawn portion and covering a portionof the first main surface, a portion of the second main surface, aportion of the second side surface, and a portion of the fourth sidesurface; a third external electrode connected to the third drawn portionand covering a portion of the first main surface, a portion of thesecond main surface, a portion of the first side surface, and a portionof the fourth side surface; and a fourth external electrode connected tothe fourth drawn portion and covering a portion of the first mainsurface, a portion of the second main surface, a portion of the secondside surface, and a portion of the third side surface; and a recess isprovided in a surface of at least two external electrodes of the firstexternal electrode to the fourth external electrode on one of the firstmain surface and the second main surface.
 2. The multilayer ceramicelectronic component according to claim 1, wherein the first externalelectrode, the second external electrode, the third external electrode,and the fourth external electrode each include an underlying electrodelayer, a first plated layer on the underlying electrode layer and on thefirst side surface, the second side surface, the third side surface, andthe fourth side surface, a second plated layer on the first platedlayer, and a third plated layer on the second plated layer.
 3. Themultilayer ceramic electronic component according to claim 1, whereinthe recess has a size not less than about 1.1% and not greater thanabout 34.9% of an area of the external electrode on the first mainsurface or the second main surface at which the recess is provided. 4.The multilayer ceramic electronic component according to claim 2,wherein the recess has a depth not less than about 2.5% and not greaterthan about 40% of a thickness of the third plated layer.
 5. Themultilayer ceramic electronic component according to claim 2, whereinthe underlying electrode layer defines and functions as a thin electrodeincluding at least one of Ni, Cr, Cu, or Ti; the first plated layer is aCu plated layer; the second plated layer is a Ni plated layer; and thethird plated layer is a Sn plated layer.
 6. The multilayer ceramicelectronic component according to claim 1, wherein a number of theplurality of ceramic layers is at least ten and at most seven hundred.7. The multilayer ceramic electronic component according to claim 1,wherein a dimension of the multilayer body in the length direction ofnot less than about 0.43 mm and not greater than about 0.73 mm.
 8. Themultilayer ceramic electronic component according to claim 1, wherein arelationship between a dimension of the multilayer body in the widthdirections and a dimension of the multilayer body in the lengthdirection satisfies about 0.85≤w/l≤about 1.0.
 9. The multilayer ceramicelectronic component according to claim 1, wherein a dimension of themultilayer body in the height direction is not less than about 50 μm andnot greater than about 90 μm.
 10. The multilayer ceramic electroniccomponent according to claim 1, wherein each of the plurality of ceramiclayers includes BaTiO₃, CaTiO₃, SrTiO₃, or CaZrO₃ as a main component.11. The multilayer ceramic electronic component according to claim 10,wherein each of the plurality of ceramic layers further includes an Mncompound, an Fe compound, a Cr compound, a Co compound, or an Nicompound as a sub-component.
 12. The multilayer ceramic electroniccomponent according to claim 1, wherein an average thickness of theplurality of ceramic layers is not less than about 0.4 μm and notgreater than about 5 μm.
 13. The multilayer ceramic electronic componentaccording to claim 1, wherein each of the plurality of internalelectrode layers includes Ni, Cu, Ag, Pd, or Au, or an alloy includingat least one of Ni, Cu, Ag, Pd, or Au.
 14. The multilayer ceramicelectronic component according to claim 1, wherein an average thicknessof each of the plurality of internal electrode layers is not less thanabout 0.2 μm and not greater than about 2.0 μm.
 15. The multilayerceramic electronic component according to claim 1, wherein a diameter ofthe recess is not less than about 20 μm and not greater than about 150μm.
 16. The multilayer ceramic electronic component according to claim2, wherein a thickness of the underlying electrode layer is not lessthan about 50 nm and not greater than about 400 nm.
 17. The multilayerceramic electronic component according to claim 2, wherein a thicknessof the underlying electrode layer is not less than about 50 nm and notgreater than about
 18. The multilayer ceramic electronic componentaccording to claim 2, wherein a thickness of the first plated layer isnot less than about 2 μm and not greater than about 8 μm.
 19. Themultilayer ceramic electronic component according to claim 2, wherein athickness of the second plated layer is not less than about 2 μm and notgreater than about 4 μm.
 20. The multilayer ceramic electronic componentaccording to claim 2, wherein a thickness of the third plated layer isnot less than about 2 μm and not greater than about 4 μm.